Provided is a wireless transmission system including a plurality of access points and an access controller. The access controller determines a start standard time for a polling period for the plurality of access points to perform polling communication with a plurality of wireless terminals. The access controller generates a scheduling setting information indicating timings when the plurality of access points perform polling communication with the plurality of wireless terminals during the polling period. The access controller transmits, to each of the plurality of access points, a polling period start signal including the start standard time and a corresponding portion of the scheduling setting information for each of the plurality of access points. The plurality of access points perform polling communication with the plurality of wireless terminals based on respective polling period start signals.